Timeline by Djordje Djukic, with additional reporting by Evan Centanni

Yemen: Who Controls What?
As we enter 2018, Yemen continues to be divided between two rival governments - the Saudi-backed administration of President Abdrabbuh Mansour Hadi, and the allegedly Iran-backed "Houthi" group that controls the capital - even while remote areas remain within the sphere of Al Qaeda in the Arabian Peninsula (AQAP). The so-called "Islamic State" (IS; formerly ISIS/ISIL) is not believed to control any towns, but is probably still present in the rural border areas between Bayda and Abyan provinces, near Lawdar.

Since our previous Yemen map report four months ago, the pro-Hadi coalition has made modest progress against both the Houthis and AQAP, though the Houthis remain firmly entrenched in their core area of control. Meanwhile, the alliance between the Houthi organization and forces loyal to former president Ali Abdullah Saleh disintegrated over the past several months. The conflict between the one-time allies culminated in open battles that brought the southern Sana'a area briefly outside of Houthi military control, ending with the death of Saleh and the rapid defeat of his faction.

Chronology of Events
The following is a timeline of major events and changes to territorial control since PolGeoNow's previous Yemen control map report of August 21, 2017.

August 23-24, 2017
A rift emerged in the Houthi-Saleh alliance, with the Houthis accusing their ally Ali Abdullah Saleh, Yemen's former president, of conducting secret negotiations with the United Arab Emirates (UAE), a member of the Saudi-led coalition supporting the rival Hadi government in Aden.

The Houthis also denounced Saleh’s description of them as a "militia", the same term Saudi Arabia uses to challenge their legitimacy. Saleh rebuked the Houthi government on television after it called his party traitors, urging them to “hold back your crazy people”, while also appealing for calm among his supporters.

August 25, 2017
A US military helicopter crashed off the coast of Yemen. All five crewmembers were rescued.

August 26, 2017Clashes erupted in Sana’a between Houthi and Saleh supporters at a Houthi checkpoint near Saleh's media office and the home of his son. Two Houthi fighters and a pro-Saleh colonel were killed.

August 28, 2017
Pro-Hadi forces captured a mountain northeast of Sa’dah and west of Al Baqqa border crossing. They had previously seized it early in 2017, but since lost it.

September 1, 2017
Seven pro-Hadi soldiers were killed and 11 wounded when the Houthis shelled their camp in Marib province during Eid prayers.

September 10, 2017
Pro-Hadi sources claimed 145 Houthi fighters had been killed in fighting since the start of the month.

September 11, 2017
A pilot from the UAE died when his plane crashed due to a technical failure. Another Emirati soldier also died of wounds received earlier in the conflict. Over 100 Emirati soldiers had died in the conflict by this point.

September 13, 2017
A Saudi pilot died when his plane crashed due to a technical failure during an operation against Al Qaeda fighters in the Abyan region.

September 14, 2017
Pro-Hadi forces captured the Wadhea district of Abyan from Al Qaeda after pushing the group out from several villages.

September 19, 2017
Pro-Hadi security forces conducted a raid against Al Qaeda in Mudiyah district of Abyan province. Later, it was reported that security forces had managed to capture the district, which had been a stronghold of Al Qaeda in the Arabian Peninsula (AQAP).

September 21, 2017
The Houthis staged a rally in Sana’a for the third anniversary of their takeover of the capital.

September 24, 2017
While speaking at the 72nd United Nations General Assembly in New York, Yemen’s Saudi-backed president, Abdrabbuh Mansour Hadi, stated that a military solution was more likely for Yemen’s civil war than a political one.

September 27, 2017
In a recorded speech broadcast on his TV station, Saleh attacked Saudi Arabia and said he would obstruct the return of Hadi to power, a move the pro-Hadi Gulf Newsreported was made under pressure from his Houthi allies. Meanwhile, Sudanese Lieutenant General Mohammed Hamdan Hamidati, commander of the Sudanese Army Rapid Support Forces, reported that 412 Sudanese soldiers, including 14 officers, had been killed so far in the conflict in Yemen. The general also stated that the Sudanese military had participated in fighting against the Houthis on 40 different fronts.

October 14, 2017
Aidarus al-Zoubaidi, a former governor of Aden and current leader of the separatist Southern Movement, announced that an independence referendum was to be held for the separation of southern Yemen from the north. Al-Zoubaidi had previously been sacked from his governor position by President Hadi, and in May 2017 subsequently announced the formation of a new council composed of senior tribal, military, and political figures seeking secession for the south. The formation of the council was rejected by Hadi. Yemeni fighters of the Southern Movement have fought alongside pro-Hadi forces against the Houthis through much of the war, and have allegedly received political and financial support from the UAE.

October 16, 2017
About 50 fighters belonging to the so-called "Islamic State" organization (IS; formerly ISIS/ISIL) were killed in US airstrikes on two training camps in Bayda province.

October 17, 2017
Two UAE pilots were killed when their military aircraft crashed 110 kilometers (70 miles) north of Sana’a.

October 29, 2017
Three members of the Iranian Revolutionary Guard Corps (IRGC) were reportedly killed in Yemen while assisting the Houthis.

October 30, 2017
Pro-Hadi forces captured the Al Qaeda stronghold of Mahfad in Abyan province and secured the highway between Aden and Azzan.

October 30 - November 1, 2017
More than 100 fighters on both sides were killed in fighting east of Sana’a, in the Nihm area, during which pro-Hadi forces claimed to have advanced, while the Houthis stated they were holding onto their positions. Additionally, more than 80 fighters on both sides died during clashes in the area of Taiz where, according to pro-Hadi sources, the internationally-backed government regained positions on a mountain that had been taken by the Houthis earlier in the week.

November 1, 2017
A Saudi-led coalition airstrike on a hotel in the north of the country left 29 people dead, including children. Meanwhile, the UN put the total death toll from the Yemen conflict at more than 8,670, of whom 60% were civilians. In addition, another 2,184 people had reportedly died due to the cholera outbreak caused by the war. In contrast, the UN previously estimated in January 2017 that at least 10,000 people had already been killed in the conflict at that point.

November 4, 2017
The Houthis launched a ballistic missile towards the Saudi capital, Riyadh, with the city's international airport as its main target. The missile was intercepted and destroyed, with debris landing inside the airport.

November 5-6, 2017
Two IS suicide bombers attacked the Hadi government's security headquarters in Aden, as well as the building hosting the criminal investigations unit, after which other fighters seized the latter building and took hostages. The hostage crisis continued until the following day, with two more suicide bombers triggering their explosives as security forces attempted to retake the building. In the end, 29 members of the security forces and six civilians were left dead.

November 6-11, 2017
The Saudi-led coalition shut down air, land, and sea routes into Yemen following the Houthi ballistic missile attack on Riyadh. Saudi Arabia asserted that blockade was necessary to stop Iran from sending additional weapons to the Houthis. Three days later, a senior UN official warned that Yemen faced the world's largest famine in decades, “with millions of victims”, if the coalition’s blockade was not lifted. The same day, the coalition opened the Wadiah border crossing with Yemen, partly easing the blockade (the Hadi-administered port of Aden had also been re-opened the previous day). On November 11, the coalition announced it would allow the resumption of international commercial flights to Yemen.

November 7, 2017
Coalition airstrikes against a village in the northwestern province of Hajjah left 50 people dead, including civilians. Meanwhile, pro-Hadi forces reportedly captured four positions in the province of Taiz.

November 12, 2017
Pro-Hadi forces reportedly seized several positions southeast of Taiz from the Houthis, as well as others northwest of Houta.

November 14, 2017
An IS suicide bomber attacked a security post in Aden, killing eight security forces members and two civilians.

November 13-17, 2017
The Saudi-led coalition won control
of an airport in eastern Yemen's Mahra province through negotiations
with local authorities, after initially being rebuffed by a Yemeni army
brigade stationed there. The coalition is reportedly in control of
Ghaydah town, while local authorities still control several ports in the
province.November 22, 2018
The Saudi-led coalition announced that it would further ease the blockade by allowing aid shipments to enter via the Houthi-held Hudaydah port and Sana'a airport.

November 29 - December 3, 2017
Houthi and pro-Saleh forces clashed with each other in the capital city of Sana’a, with pro-Saleh fighters securing the southern part of the city, specifically the Hadda district. The city's northern part remained under Houthi control. Saleh then declared that a “new page” would be turned with the Saudi-led coalition if it stopped its attacks on Yemen and lifted the blockade of the country. The Houthis called Saleh’s overture to the Saudis “a coup”, while the coalition praised him. The Guardian described the fighting as the disintegration of the Houthi-Saleh alliance.

On December 3, the Saudi-led coalition conducted airstrikes in Sana’a in support of Saleh loyalists. Meanwhile, an airstrike in the province of Sa’dah left 12 civilians dead. At this point, the Houthis claimed to have secured control over most of Sana’a, something that Saleh loyalists denied. The Houthis also said they had seized the city of Dhamar south of Sana’a from pro-Saleh forces.

December 9-10, 2017
Pro-Hadi forces captured the Hays district, just inland from Khoukha, after which they entered a third district of Hudaydah province and reportedly seized it the following day. However, it was reported on the same day that the Houthis had cut off the road between Mukha (Mocha) and Khoukha, forcing pro-Hadi troops to retreat from Hays.

December 15, 2017
Pro-Hadi forces captured the Usaylan district of Shabwa province, on the eastern front with the Houthis, after which fighting moved to the outskirts of Baihan. Later, some pro-Hadi sources claimed their forces captured the Baihan district, while others reported they had seized several areas but that the district was still contested. It was subsequently confirmed that the town of Baihan had been captured by pro-Hadi forces.

December 20, 2017
For a second time, the Houthis launched a ballistic missile towards the Saudi capital Riyadh, with the main target being the royal Yamama Palace. The missile was intercepted and destroyed.

December 25, 2017
Pro-Hadi forces reportedly pushed into Bayda province and claimed to have captured two districts there.

December 28, 2017
A top UN official reported that the Saudi-led coalition had killed 109 civilians in airstrikes over the previous ten days, including 54 at a market and 14 members of one family. The coalition denied this, asserting that the official's information was not credible, and accusing him of siding with the Houthis.

December 31, 2017
Pro-Hadi troops reportedly captured most of the Khab Al Sha’af district, the largest in Jawf province. Meanwhile, fighting was ongoing in the two districts of Bayda province that pro-Hadi forces had earlier claimed to have seized.

January 3, 2018Fighting took place in the agricultural areas of Hays at the town's entrances. Meanwhile, a Houthi attack on pro-Hadi positions in the coastal areas of Hudaydah was repelled.

January 5, 2018
The chief of staff of Yemen's pro-Hadi army was injured in a land mine explosion in the Khab Al Sha'af area of Jawf province, while state-run media claimed that government fighters with Saudi air support had captured a mountain north of Al Hazm. The same day, Houthi forces fired another ballistic missile, this time at a military camp on the Saudi side of the border in the city of Najran. Houthi media claimed the missile hit its target, while Saudi Arabia claimed to have intercepted the missile in mid-air.